FIELD OF THE INVENTION AND PRIOR ART
The invention relates to hose end units and more particularly relates to a hose end unit comprising a hose end portion having at least an inner cylindrical elastomeric liner, for example rubber, and a reinforcement layer surrounding the liner, and an end fitting of the kind comprising an insert which enters into the end portion of the hose and a ferrule which surrounds the end portion of the hose, a plurality of projections being provided on the ferrule, the ferrule being swaged around the insert so that the hose end portion is gripped between the insert and the ferrule by the projections. The hose end portion may have an outer cover or the outer cover may be removed. Such an end unit will hereinafter be referred to as "of the kind described". In end units of the kind described, the gap between the wire reinforcement and the peak of a projection on the insert is referred to as "the extrusion gap" since it is through this gap that the rubber layer tends to extrude when the hose is subjected to internal pressure due to the separation force induced inside the end fitting resulting from the above mentioned internal pressure, since the initial pressure in the rubber will decay to zero due to volumetric displacement of the liner in the axial direction. This phenomenon can lead to failure of the end fitting and, in known compression end fittings, it is found that the fitting will separate from the hose at lower than the burst pressure of the hose.